Mark One Eyeball is a Colonial military term for visual reconnissance or flight plans improvised by the pilots themselves when searching for wreckage, survivors or managing other mission objectives. This becomes necessary when the use of technology isn't applicable or available due to unforeseen, unpredictable, or hazardous changes in completing a mission or task.
Commander Adama ordered such a search for Kara "Starbuck" Thrace (TRS: "You Can't Go Home Again") when her ship was heavily damaged by an encounter with a Cylon Raider squadron (TRS: "Act of Contrition").
The CAP guarding the Majahual during a critical mining operation must use their Mark One Eyeballs when DRADIS cannot distinguish between the rock and debris in the asteroid system and enemy fighters harassing the mining operation (TRS: "Scar").
- This term is actual British military slang for eyes or eye sight, derived from British Royal Navy nomenclature for distinguishing sequential variations of a piece of equipment (i.e., "Mark 13 Depth Charge"). Since the human eye has not changed, it is called the Mark I Eyeball. The term is typically used when someone relies too much on their equipment: "Use your Mark One Eyeball!". It is used likewise in the United States military and other predominantly English-speaking countries.